The use of isometric as compared to rhythmic exercise in the general field of athletic strength development, as well as a therapy for strength recovery has been the subject of somewhat controversial discourse over the past decades. In general, such exercise has been considered to promote, for example, coronary risk factors. See generally:                (1) Vecht R J, Graham G W S, Sever P S. “Plasma Noradrenaline Concentrations During Isometric Exercise.” Brit Heart J. 1978;40:1216-20.        (2) Chrysant S G. “Hemodynamic Effects of Isometric Exercise in Normotensive Hypertensive Subjects”: Hypertension. Angiology 1978:29(5):379-85.        
However, as such attitudes persisted, some investigators commenced to observe contradictions to these generally accepted beliefs. See for, example, the following publications:                (3) Buck, et al., “Isometric Occupational Exercise and the Incidence of Hypertension”, J. Occup. Med., 27:370-372, 1985        (4) Choquette, et al., “Blood Pressure Reduction in ‘Borderline’ Hypertensivies Following Physical Training” Can. Med. Assoc. J. 1108:699-703, 1973.        (5) Clark, et al., “The Duration of Sustained Contractions of the Human Forearm of Different Muscle Temperatures”, J. Physiol., 143:454-473, 1958.        (6) Gilders, et al., “Endurance Training and Blood Pressure in Normotensive and Hypertensive Adults”, Med. Sci. Sports Exerc. 21:629-636, 1989.        (7) Hagberg, et al., “Effect of Weight Training on Blood Pressure and Hemodynamics in Hypertensive Adolescents”, J. Pediatr. 1104:147-151, 1984.        (8) Harris, et al., “Physiological Response to Circuit Weight Training in Borderline Hypertensive Subjects”, Med. Sci. Sports Exerc., 19:246-252, 1987.        (9) Hurley, et al., “Resistive Training Can Induce Coronary Risk Factors Without Altering VO2 max or Percent Body Fat” Med. Sci. Sports Exerc. 20:150-154, 1988.        (10) Hypertension Detection and Follow-Up Program Cooperative Group, “The Effect of Treatment on Mortality in ‘Mild’ Hypertension”, N. Engl. J. Med., 307:976-980, 1982.        (11) Kiveloff, et al., “Brief Maximal Isometric Exercise in Hypertension”, J. Am. Geriatr. Socl, 9:1006-1012, 1971.        (12) Merideth et al., “Exercise Training Lowers Resting Renal but not Cardiac Sympathetic Activity in Humans”, Hypertension, 18:575-582, 1991.        (13) Seals and Hagberg, “The Effect of Exercise Training on Human Hypertension: A Review”, Med. Sci. Sports Exerc., 16:207-215, 1984.        (14) Hanson P, Nagle F. “Isometric Exercise: Cardiovascular Responses in Normal and Cardiac Populations.” Cardiology Clinics 1987;5(2): 157-70.Such speculation on the part of these early observers was confirmed by Wiley in the 1990s, as described in U.S. Pat. No. 5,398,696 entitled “Isometric Exercise Method for Lowering Resting Blood Pressure and Grip Dynamometer Useful Therefore”, issued Mar. 21, 1995 and as described in the following publication:        (15) Wiley, et al., “Isometric Exercise Training Lowers Resting Blood Pressure”, Med. Sci. Sports Exerc. 29:749-754, 1992.        
With the approach or protocol developed by Wiley, the isometric regimen is closely controlled both in terms of exerted force and in the timing of trials or exertions.
In contrast, earlier subjects or trainees undergoing isometric exercise stressed the involved musculature to their full or maximum capability (publication (11)) or at some submaximal force as long as it could be sustained, in either case only terminating with the onset of unendurable fatigue. Such approaches often have incurred somewhat deleterious results as evidenced by the injuries sustained in consequence of improper weightlifting procedures. Weightlifting procedures or endeavors exhibit a significant isometric factor. See generally:                (16) Lind A R. “Cardiovascular Responses to Static Exercise” (Isometrics, Anyone?) Circulation 1970;41(2): 173-176.        (17) Mitchell J H, Wildenthal K. “Static (Isometric) Exercise and the Heart: Physiological and Clinical Considerations”. Ann Rev Med 1974;25:369-81.        
The diagnosis of patient hand-arm strength using isometric-based testing has been employed by physiologists, physical therapists and medical personnel for over three decades. These procedures function to evaluate hand-arm trauma or dysfunction and involve the patient use of a handgrip-based dynamometer. The dynamometer is grasped by the patient and squeezed to a maximum capability under the verbal instruction of an attending therapist or diagnostician. The hand dynamometer most widely used for these evaluations incorporates a grip serving to apply force through closed circuit hydraulics to a force readout provided by an analog meter facing outwardly so as to be practitioner readable. Adjustment of the size of the grip of the dynamometer is provided by inward or outward positioning of a forwardly disposed grip component. The dynamometers currently are marketed under the trade designation: “Jamar Hydraulic Hand Dynamometer” by Sammons Preston of Bolingbrook, Ill. An extended history of use of these dynamometers has resulted in what may be deemed a “standardization” of testing protocols. For instance, three of the above-noted grip length adjustments are employed in a standardized approach and verbal instructions on the part of the testing attendant, as well as the treatment of force data read from the analog meter are now matters of accepted protocol. In the latter regard, multiple maximum strength values are recorded, whereupon average strengths, standard deviations and coefficients of variation are computed by the practitioner. In one test, the instrument is alternately passed between the patient's right and left hands to derive a maximum strength output reading each 1.5 seconds or 2.5 seconds. Reading and hand recording strength values for such protocols has remained problematic. The protocols, for example, have been the subject of recommendations by the American Society of Hand Therapist (ASHT) and have been discussed in a variety of publications including the following:                (18) Mathiowetz V., Federman S., Wiemer D. “Grip and Pinch Strength: Norms for 6 to 19 Year Olds.” The American Journal of Occupational Therapy 40:705-11, 1986.        (19) Mathiowetz V., Donohoe L., Renells C. “Effect of Elbow Position on Grip and Key Pinch Strength.” The Journal of Hand Surgery 10A:694-7, 1985.        (20) Mathiowetz V., Dove M., Kashman N., Rogers S., Volland G., Weber K. “Grip and Pinch Strength: Normative Data for Adults.” Arch Phys Med Rehabilitation 66:69-72, 1985.        (21) Mathiowetz V., Volland G., Kashman N., “Reliability and Validity of Grip and Pinch Strength Evaluations.” The Journal of Hand Surgery 9A:22-6, 1984.        
In about 1998, the above-noted Wiley protocols as described in connection with publication (12) above were incorporated in a compact, lightweight isometric device. Described in detail in U.S. Pat. No. 5,904,639 entitled “Apparatus, System, and Method for Carrying Out Protocol-Based Isometric Exercise Regimens” by Smyser, et al., the hand-held dynamometer has a hand grip which incorporates a load cell assembly. Extending from the hand grip is a liquid crystal display and two user actuated control switches or switch buttons. The display is mounted in sloping fashion with respect to the grip such that the user can observe important visual cues or prompts while carrying out a controlled exercise regimen specifically structured in terms of force values and timing in accordance with the Wiley protocols. This device is therapeutic as opposed to diagnostic in nature and is microprocessor driven with archival memory. External communication with the battery powered instrument is made available through a communications port such that the device may be configured by programming and, additional data, such as blood pressure values and the like may be inserted into its memory from an external device. Visual and audible cueing not only guides the user through a multi-step protocol but also aids the user in maintaining pre-computed target level grip compression levels.
Of course, it will be beneficial to incorporate improved diagnostic features for hand-arm evaluation techniques with therapist or practitioner designed therapeutic protocols specifically tailored to the condition of a given patient and which provide a control over such therapies clearly establishing such therapies as beneficial to strength development and recovery.